The reciprocal of \displaystyle\frac{3}{10} is \displaystyle\left(\frac1x+1\right). What is the value of x?
Answer Choices
A. \displaystyle\frac73
B. \displaystyle\frac{3}{13}
C. \displaystyle\frac37
D. \displaystyle\frac53
E. \displaystyle\frac35